Date: Thu, 1 Feb 1996 22:34:44 +0200 (EET) From: Seppo Kallio <kallio@beeblebrox.pccc.jyu.fi> To: Terry Lambert <terry@lambert.org> Cc: terry@lambert.org, ahill@interconnect.com.au, pbanks@candle.com, questions@FreeBSD.ORG Subject: Re: Run BSD under DOS Message-ID: <Pine.BSF.3.91.960201222633.6023F-100000@beeblebrox.pccc.jyu.fi> In-Reply-To: <199602011750.KAA13328@phaeton.artisoft.com>
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On Thu, 1 Feb 1996, Terry Lambert wrote: > > I am using netboot in a lab. It works. > > > > Maybe dosboot (waht is fbsdboot?) is faster to boot. How could I test it? > > Is there instructions somewhere? > > /sys/i386/boot/dosboot/readme. > > 8-). > > > Terry Lambert > terry@lambert.org I know :-) it is after this paragraph. Terry, I am 100% sure you do not want I try it after rereading it. It is some time I read it first time and understood very little and ... some base level questions: how to define root partition, swap, /etc, must I have FreeBSD partition ... OK maybe the idea of this is to boot FreeBSD from dos and have a FreeBSD partition ready to mount? Yes so it must be. I tryet to use it as netboot having NFS root etc. Everything is so opvious to you experts that you do not see how little you tell what is the purpose of your tools. Seppo ------------ 10:24pm@beeblebrox:~% more /sys/i386/boot/dosboot/readme Hi Everybody! This is version 1.5 of "fbsdboot", a program that allows you to boot a kernel from a MS-DOS partition or a FreeBSD partition. This program runs using DOS. It works with various memory managers (like EMM386, 386MAX) under certain circumstances. First, a FreeBSD kernel is always loaded to memory starting at 0x100000. To assure that loading the kernel *does not* overwrite memory used by memory managers, high memory for the kernel is allocated and after loading the kernel it's moved to 0x100000. Second, there are many ways to switch to protected mode which is necessary to start the kernel. Each BIOS gives you the possibility to use INT15H (AH=89H) to do that. But some memory-managers like 386max does not allow you to use this method. An other way to do the switch is to use DPMI services, but they do not guarantee, that the protected mode application is executed with privilege level 0. Therefore this method is *not* used. VCPI services offer another way to switch to protect to switch to protected mode , and VCPI servers are built into "emm386.exe", "386max" and "qemm". That's why, this method is implemented in fbsdboot.exe. Fbsdboot.exe tries to switch to protected mode using VCPI services. If they're not available INT15H is used to do the switch. If that fails, it's not possible for this version of fbsdboot.exe to boot a kernel :-(. You can get commandline options of fbsdboot if you start it with "-?" as option! I don't know, if fbsdboot works with QEMM, as I don't have the possibility to test it. Enjoy and have fun! Christian. cg@fimp01.fim.uni-linz.ac.at PS: Many thanks to Bruce Evans for his assistance! or his assistance!
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